Booting Processes

The names of startup scripts might change from one release to
another.

You start the operating system on a host.

The kernel runs /sbin/init, as part of
the booting process.

/sbin/init runs the /etc/rcS.d/S30rootusr.sh. startup script.

The script runs a number of system startup tasks, including
the establishment of the minimum host and network configurations for diskless
and dataless operations. /etc/rcS.d/S30rootusr.sh also
mounts the /usr file system.

If the local database files contain the required configuration
information (host name and IP address), the script uses it.

If the information is not available in local host configuration
files, /etc/rcS.d/S30rootusr.sh uses RARP to acquire the
host's IP address.

If the local files contain domain name, host name, and default
router address, the machine uses them. If the configuration information is
not in local files, then the system uses the Bootparams protocol to acquire
the host name, domain name, and default router address. Note that the required
information must be available on a network configuration server that is located
on the same network as the host. This requirement is necessary because no
internetwork communications exist at this point.

After /etc/rcS/S30rootusr.sh completes
its tasks and several other boot procedures have executed, /etc/rc2.d/S69inet runs. This script executes startup tasks that must be completed
before the name services (NIS, NIS+, or DNS) can start. These tasks include
configuring the IP routing and setting the domain name.

At completion of the S69inet tasks, /etc/rc2.d/S71rpc runs. This script starts the NIS, NIS+, or DNS
name service.

After /etc/rc2.d/S71 runs, /etc/rc2.d/S72inetsvc runs. This script starts up services that depend on the presence
of the name services. S72inetsvc also starts the daemon inetd, which manages user services such as telnet.